Use larger overlap if it is sufficient to cover the isolation width

surface_vectorial.cpp

@@ -652,16 +652,17 @@ vector<pair<linestring_type_fp, bool>> Surface_vectorial::get_single_toolpath(
     if (!isolator) {
       extra_passes = 0;
     } else {
-      auto computed_extra_passes = std::ceil(
+      int computed_extra_passes = int(std::ceil(
           (isolator->isolation_width - tool_diameter) /
-          (tool_diameter - overlap_width) - isolator->tolerance); // In case it divides evenly, do fewer passes.
+          (tool_diameter - overlap_width) - isolator->tolerance)); // In case it divides evenly, do fewer passes.
       if (isolator->extra_passes >= computed_extra_passes) {
         extra_passes = isolator->extra_passes;
       } else {
         extra_passes = computed_extra_passes;
         // The actual overlap that we'll use is such that the final pass
         // will exactly cover the isolation width and no more.
-        overlap = overlap_width;
+        overlap = tool_diameter - ((isolator->isolation_width - tool_diameter) /
+                                   (extra_passes + isolator->tolerance));
       }
     }
     const bool do_voronoi = isolator ? isolator->voronoi : false;

testing/gerbv_example/backtrack/expected/test-F.Cu-front-0.3mm.nc

@@ -21,86 +21,87 @@ G04 P1.00000 (Wait for spindle to get up to speed)
 G04 P0 ( dwell for no time -- G64 should not smooth over this point )
 G00 Z0.50000 ( retract )
 
-G00 X0.00000 Y0.34511 ( rapid move to begin. )
+G00 X0.00000 Y0.34605 ( rapid move to begin. )
 G01 F25.00000
 ( Mill infeed pass 1/1 )
 G01 Z-0.15000
 G04 P0 ( dwell for no time -- G64 should not smooth over this point )
 G01 F100.00000
-G01 X0.00000 Y0.34511
-G01 X0.00000 Y9.81484
-G01 X0.03139 Y9.87359
-G01 X0.05893 Y9.91479
-G01 X0.12001 Y9.99310
-G01 X0.19195 Y10.06157
-G01 X0.29238 Y10.13455
-G01 X0.34293 Y10.16000
-G01 X14.89479 Y10.15997
-G01 X14.95359 Y10.12855
-G01 X14.99479 Y10.10102
-G01 X15.07310 Y10.03993
-G01 X15.15735 Y9.94875
-G01 X15.23088 Y9.83874
-G01 X15.23997 Y9.82167
-G01 X15.23997 Y0.34079
-G01 X15.18102 Y0.24516
-G01 X15.11993 Y0.16685
-G01 X15.04800 Y0.09837
-G01 X14.94757 Y0.02540
-G01 X14.89707 Y0.00000
-G01 X0.33823 Y0.00000
-G01 X0.23731 Y0.06220
-G01 X0.12708 Y0.16210
-G01 X0.04313 Y0.26439
-G01 X0.00000 Y0.34511
-G01 X0.13297 Y0.70998
-G01 X0.13297 Y9.44999
-G01 X0.13513 Y9.49409
-G01 X0.15128 Y9.58637
-G01 X0.17689 Y9.67080
-G01 X0.21847 Y9.74860
-G01 X0.28674 Y9.84199
-G01 X0.35392 Y9.90343
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-G01 X0.51298 Y9.99028
-G01 X0.59736 Y10.01588
-G01 X0.68511 Y10.02454
-G01 X14.52989 Y10.02698
-G01 X14.61778 Y10.01834
-G01 X14.66637 Y10.00867
-G01 X14.75080 Y9.98306
-G01 X14.82860 Y9.94148
-G01 X14.92199 Y9.87321
-G01 X14.98343 Y9.80603
-G01 X15.03243 Y9.73267
-G01 X15.07101 Y9.65017
-G01 X15.09834 Y9.53778
-G01 X15.10698 Y9.44999
-G01 X15.10698 Y0.70998
-G01 X15.09834 Y0.62217
-G01 X15.08867 Y0.57358
-G01 X15.07343 Y0.51671
-G01 X15.05090 Y0.46233
-G01 X14.99395 Y0.37015
-G01 X14.95321 Y0.31796
-G01 X14.88603 Y0.25651
-G01 X14.83187 Y0.21839
-G01 X14.77274 Y0.18862
-G01 X14.66411 Y0.14889
-G01 X14.59885 Y0.13757
-G01 X14.52999 Y0.13297
-G01 X0.70998 Y0.13297
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-G01 X0.50978 Y0.16894
-G01 X0.42728 Y0.20752
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-G01 X0.14889 Y0.57584
-G01 X0.13757 Y0.64110
-G01 X0.13297 Y0.70998
+G01 X0.00000 Y0.34605
+G01 X0.00000 Y9.81390
+G01 X0.03175 Y9.87334
+G01 X0.05928 Y9.91456
+G01 X0.12035 Y9.99279
+G01 X0.19223 Y10.06122
+G01 X0.29261 Y10.13417
+G01 X0.34392 Y10.15997
+G01 X14.89385 Y10.15997
+G01 X14.95334 Y10.12820
+G01 X14.99456 Y10.10067
+G01 X15.07279 Y10.03960
+G01 X15.15702 Y9.94847
+G01 X15.23047 Y9.83851
+G01 X15.23997 Y9.82073
+G01 X15.24000 Y0.34168
+G01 X15.18067 Y0.24539
+G01 X15.11960 Y0.16716
+G01 X15.04772 Y0.09873
+G01 X14.94734 Y0.02578
+G01 X14.89608 Y0.00000
+G01 X0.33917 Y0.00000
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+G01 X0.12738 Y0.16243
+G01 X0.04348 Y0.26464
+G01 X0.00000 Y0.34605
+G01 X0.13320 Y0.70998
+G01 X0.13320 Y9.44999
+G01 X0.13536 Y9.49406
+G01 X0.15151 Y9.58634
+G01 X0.17709 Y9.67069
+G01 X0.21867 Y9.74847
+G01 X0.28689 Y9.84184
+G01 X0.35408 Y9.90326
+G01 X0.40818 Y9.94136
+G01 X0.51308 Y9.99007
+G01 X0.59741 Y10.01568
+G01 X0.68511 Y10.02431
+G01 X14.52989 Y10.02675
+G01 X14.61773 Y10.01812
+G01 X14.66634 Y10.00844
+G01 X14.75069 Y9.98286
+G01 X14.82847 Y9.94128
+G01 X14.92184 Y9.87306
+G01 X14.98326 Y9.80587
+G01 X15.03225 Y9.73257
+G01 X15.07081 Y9.65012
+G01 X15.09812 Y9.53773
+G01 X15.10675 Y9.44999
+G01 X15.10675 Y0.70998
+G01 X15.09812 Y0.62222
+G01 X15.08844 Y0.57361
+G01 X15.07322 Y0.51679
+G01 X15.05072 Y0.46243
+G01 X14.99377 Y0.37028
+G01 X14.95306 Y0.31811
+G01 X14.88587 Y0.25669
+G01 X14.83177 Y0.21859
+G01 X14.77267 Y0.18882
+G01 X14.66405 Y0.14910
+G01 X14.59885 Y0.13780
+G01 X14.52999 Y0.13320
+G01 X0.70998 Y0.13320
+G01 X0.66589 Y0.13536
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+G01 X0.14910 Y0.57589
+G01 X0.13780 Y0.64110
+G01 X0.13320 Y0.70998
 G01 X0.35796 Y0.70998
 G01 X0.36716 Y0.63053
 G01 X0.37755 Y0.59908
@@ -177,7 +178,7 @@ G01 X6.35815 Y3.19151
 G01 X6.51314 Y3.10802
 G01 X6.89734 Y2.94297
 G01 X7.17702 Y2.85316
-G01 X7.17624 Y2.84958
+G01 X7.17624 Y2.84960
 G01 X7.17702 Y2.85316
 G01 X7.41093 Y2.83144
 G01 X7.82914 Y2.82994
@@ -204,12 +205,12 @@ G01 X9.85142 Y5.52384
 G01 X9.83417 Y5.57959
 G01 X9.68934 Y5.97218
 G01 X9.50973 Y6.34266
-G01 X9.51337 Y6.34512
+G01 X9.51337 Y6.34510
 G01 X9.50973 Y6.34266
 G01 X9.43605 Y6.43387
 G01 X9.14814 Y6.73725
 G01 X8.88180 Y6.96841
-G01 X8.88423 Y6.97207
+G01 X8.88421 Y6.97207
 G01 X8.88180 Y6.96841
 G01 X8.72681 Y7.05190
 G01 X8.34260 Y7.21698